Drive apparatus for overhead doors



July 28, 1970 A R. L. KUSS 3,521,693

DRIVE APPARATUS FOR OVERHEAD DOORS Filed Jan. 16, 1969 INVENTOR. gALPI-I L. s 5.

I 'I' ITE-Z- ATT Q United States Patent U.S. Cl. 160-243 3 Claims ABSTRACT OF THE DISCLOSURE An apparatus for raising and lowering flexible doors on a roller by means of an endless chain which imparts torque upon the roller to wind or unwind it in the flexible sheet which comprises the door. The apparatus includes a tubular drive sleeve secured to the drive chain sprocket, which sleeve is driven by a primary source of motive power, such as an electric motor. An auxiliary source of motive power, such as a manual chain fall, includes a chain fall. sprocket secured to an axle extending through the tubular drive sleeve and engaged to the shaft of the primary source of motive power. Movement of the flexible door may be effected, when the source of primary power is disabled, by rotation of the chain fall sprocket to rotate the axle which engages and turns the shaft of the primary source which in turn drives the tubular sleeve and the drive chain sprocket to thus move the flexible door.

This invention relates to a drive mechanism particularly adapted for use in raising and lowering overhead flexible doors of the type described in my U.S. Pat. 3,398,779.

More specifically, the object of this invention is to provide a drive mechanism for an endless chain which raises or lowers such flexible doors, which mechanism includes a first or primary source of motive power, such as an electric motor, and an auxiliary or emergency source, such as a manually-operated chain fall, which can be used in the event of failure of the primary source.

The apparatus is designed so that it automatically compensates for differences in torque and speed input between the primary and secondary sources of power, and also provides a simple means of disconnecting the secondary source of power when it is not needed.

Finally, the apparatus is designed so that the secondary source of power, such as the manually-operated chain fall, may be positioned on the outside of the door or building for use at any time when the door is closed.

Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings in which:

FIG. 1 is a view in perspective of the drive mechanism of this invention as it is used for raising and lowering a flexible door of the type described in my U.S. Pat. 3,398,779;

FIG. 2 is a cross-sectional view of the drive mechanism, taken along line 2--2 of FIG. 1 and shown on an enlarged scale; and

FIG. 3 is a top view of the drive mechanism taken along line 3-3 of FIG. 1, also shown on an enlarged scale, showing the drive mechanism and the manner in which the motor is secured thereto.

Referring first to FIG. 1, the flexible door includes a sheet whose lower edge is wound upon the door roller 11 and whose upper edge is attached to the building overhead or lintel 12. This attachment can be made by use of the device 13 which is a subject matter of my U.S. patent application Ser. No. 754,862, filed Aug. 23, 1968. At the end of the roller 11, an endless chain 14 extends along the vertical path of the roller and engages the drive sprockets which travel with the roller and which are fully described in said U.S. Pat. 3,398,779.

3,521,693 Patented July 28, 1970 The drive mechanism which is the subject of this invention is positioned at the top of the run of the endless chain 14, as seen in FIG. 1, and is supported by a flanged attachment bracket 15 which is secured to the building lintel 12 and associated wall structures.

Referring to FIG. 2, the flanged bracket includes a plate 16 which may be directly bolted or otherwise attached to the building lintel 12 and a flanged support arm 17 from which is suspended a pair of spaced-apart bearings 18 and 19. A tubular drive sleeve 20 is journaled for rotation within the bearings 18 and 19 and is held against axial movement within the bearings 18 and 19 by a pair of collars 21 and 22. A pulley 23 is secured on the inward end of the tubular drive sleeve 20, as seen in FIG. 3. The tubular drive sleeve 20 is connected to a motor 24 by means of a V-belt 25 which extends around the pulley 23 and a smaller pulley 26 secured to the drive shaft 27 of the motor 24.

Referring again to FIG. 2, an axle 28 extends through the tubular drive sleeve 20 and is supported therein by a pair of bearings 29 and 30 and by a third bearing 31 secured to the plate 16 of the flanged bracket 15 so that the axle 28 may rotate independently of the tubular drive sleeve 20. On one end of the axle 28 is secured a sprocket 32 for connection to a source of auxiliary power, such as the manually driven chain fall 33 which extends on the outside of the door and building, as shown in FIG. 1. On the other, inner end of the axle 28 is secured a pulley 34 which is connected to the shaft 27 of the motor 24 by a second V-belt 35 which extends around the pulley 34 and a similar pulley 36 secured to the motor shaft 27. Finally, a drive sprocket 37 for connection to the endless chain 14 which moves the door roller 11 is secured to the outside of the tubular drive sleeve 20 between the bearings 18 and 19 as shown in FIG. 2.

The mechanism thus described functions as follows. The motor 24 is considered to be the normal source of motive power for raising and lowering the door. When the motor 24 is actuated, in either direction, rotation of the motor shaft 27 turns the tubular sleeve 20 through the connecting V-belt 25 and associated pulleys 23 and 26, which thus turns the drive sprocket 37 to move the chain 14 to raise or lower the door. The electrical connections of the motor 24, of course, enable the operator to selectively move the door in either direction. At the same time, the axle 28 is rotated by the motor through the V-belt 35 and associated pulleys 34 and 36. In this mode of operation, the chain fall 33 may be disengaged by slipping the chain off of the sprocket 32 and letting it rest upon the axle 28 or upon some other support mechanism (not shown) for supporting the chain when it is not engaged with the sprocket 32. The speed of movement of the drive chain 14 and thus of the door is controlled by selection of the relative diameters of the drive sprocket 37, the pulley 23 and the pulley 26. As shown in FIG. 3, a speed reduction is elfected by using a pulley 23 of a relatively large diameter in relation to that of pulley 26. The actual diameters and proportions of these pulleys should be selected to effect the proper speed and torque ratios required for moving the door, as dictated by the size and horsepower of the motor 24, weight and height of the door, etc.

The mechanism provides a secondary source of power for raising and lowering the door in the event that there is a power failure or in the event that some other malfunction causes the motor 24 not to operate. When using this secondary source of power, the chain fall 33 is attached to its sprocket 32, and rotation of the sprocket 32 by movement of the chain fall will move the door as follows. Rotation of the sprocket 32 turns its axle 28 and thus the pulley 34 which causes the motor shaft 27 to be turned by the pulley 36. Rotation of the motor shaft 27 drives the tubular drive sleeve 20 through the belt 25 3 and its associated pulleys 23 and 26 to thus turn the drive sprocket 37 to move the drive chain 14 and thus the door. When using this mode of auxiliary power, a suitable mechanical advantage may be obtained such as a speed reduction and increase in torque by using a large diameter sprocket 32. Again, the selection of the size of this sprocket depends upon the weight of the particular door, etc., and will be apparent to those skilled in the art.

The mechanism thus described has the advantage that it utilizes a primary and secondary source of power which can be used to raise and lower the door without the necessity of clutches or transmissions for disconnecting the unneeded source of power. In addition, if a third source of power, such as a second chain fall, is desired for inside of the building, the axle 28 may be extended and a second sprocket may be included inside the door. In this case, the door could be manually opened from either inside or outside the building in the event of power failure or of other failure of the motor 24.

Finally, it will be seen that, because movement of the door by means of the auxiliary source of power, such as the chain fall 33, requires movement of the entire mechanism including the motor 24, a damping effect due to the inertia of the parts is created which prevents the system, including the gear mechanism at the end of the door roller 11, from being shocked due to non-uniform application of force on the chain fall by the operator or other sudden forces which might tend to place undue stress upon the system.

It will be apparatus to those skilled in the art that various modifications of the preferred embodiment described above may be made to effect the same advantages of operation which constitute the objects of this invention. Such changes may be made without departing from the scope of the attached claims.

I claim:

1. A drive apparatus for moving a flexible door by means of an endless chain comprising, in combination, a tubular sleeve journaled for rotation above the path of said endless chain and at the top of the space covered by said flexible door, a drive chain sprocket engaging said chain and secured to said tubular sleeve above said chain path whereby rotation of said sleeve will drive said chain to move said door, a motor having its output shaft engaged to rotate said tubular sleeve, an axle extending through said tubular sleeve and coaxially journaled for rotation independently of said sleeve, with one end of said axle extending beyond said sleeve and positioned outside of said flexible door and the other end extending beyond said sleeve and engaged to the output shaft of said motor whereby rotation of said axle causes rotation of said motor output shaft and thus rotation of said sleeve, and means secured to said one end of said axle outside of said flexible door for engagement with an auxiliary source of power.

2. The drive apparatus of claim 1 wherein said means secured to said one end of said axle outside of said flexible door is a chain sprocket for connection to a chain fall.

3. A drive apparatus for moving a flexible door by means of an endless drive chain, comprising, in combination, a tubular sleeve journaled for rotation on an axis substantially normal to the plane of said door and at one end of the path of said endless drive chain, a drive chain sprocket coaxially secured to said tubular sleeve and positioned to engage said drive chain whereby rotation of said tubular sleeve will move said chain to drive said flexible door, a primary source of power on one side of said door having an output shaft connected to effect rotation of said tubular sleeve, an axle extending through said tubular sleeve and journaled for rotation independently thereof, means secured to one end of said axle on the other side of said door for connection to a secondary source of power, and means secured to said axle and engaging said output shaft of said primary source of power whereby rotation of said axle by said secondary source of power will effect rotation of said output shaft, said tubular sleeve and said drive chain sprocket to move said flexible door.

References Cited UNITED STATES PATENTS 2,454,988 11/1948 Bunker 74-625 X 2,670,065 2/1954 Stevens -133 X 2,718,395 9/1955 Ehrlich 74-625 2,819,628 1/1958 Warolaw 160-133 3,256,994 6/1966 Koelsch 74-665 3,398,779 8/1968 Kuss 160-243 3,439,638 4/1969 Zuk 112-219 PETER M. CAUN, Primary Examiner 

